RESEARCH

RESEARCH

For nearly two decades, Alaska Whale Foundation has been supporting impassioned scientists who promote understanding and conservation of marine mammals and their habitat.

WHALE ACOUSTICS

WHALE ACOUSTICS

WHALE ACOUSTICS

WHALE ACOUSTICS

HORSEY SOUNDS. DRIPPING WATER. AHOOGAS. It may come as a surprise, but humpbacks have a diverse and colorful vocal repertoire, and they like to chatter! For two field seasons, AWF student interns drifted quietly in front of AWF’s research station at the historic Five Fingers Lighthouse and listened to humpback whales talk amongst themselves. Working in teams, some students observed the behavior of the whales from the lighthouse tower, while others floated nearby recording their vocalizations with hydrophones - underwater microphones.

Little is known about the role that communication plays among humpback whales. With this in mind, AWF analyzed hundreds of humpback vocalizations recorded at the lighthouse. Humans are champion acoustic discriminators, so AWF worked with student volunteers to detect subtle differences among vocalizations and classify them into different ‘call types’. The classification scheme was then corroborated with statistical analysis techniques. As a result, AWF created the first comprehensive catalog of vocalizations produced by humpback whales on their foraging grounds.

EAR TO THE HYDROPHONE Michelle Fournet takes a turn listening to the humpbacks with a pair of hydrophones. Fournet, an Oregon State University graduate student, lived full time in the lighthouse and coordinated the efforts of student volunteers.

A LONG WAY FROM HOME. Student volunteers traveled from around the world to study humpback vocalizations with AWF in Frederick Sound, Southeast Alaska

With the catalog complete, the next step is to investigate the role that these vocalizations play among foraging whales. This will involve correlating the various vocalizations with specific whale behavioral and social patterns observed from the lighthouse tower. Ultimately, we hope to use this information to anticipate some of the consequences humpbacks will face as ocean noise continues to rise.

Did you know a whale could sound like horse? Or like an owl? Like a squeegee on a wet glass surface? Or like the zipper of a jacket being quickly zipped up to keep out the building winds? Or like a deep rumbling purr or growl of a large cat?

Similar to the watch-keeping birds on the Five Finger Islands, we too maintain our vigilance by monitoring the underwater sounds produced by humpback whales in Frederick Sound.

Aug 12, 2014

BUBBLE-NETTING

RESEARCH ON THE BUBBLE-NETTING WHALES OF ALASKA

BUBBLE-NETTING

RESEARCH ON THE BUBBLE-NETTING WHALES OF ALASKA

ENDURING BONDS between ‘coworkers’ that persist for decades? Cooperation between individuals that are related, not as kin, but in their pursuit of the same goals? Different tasks for different individuals? These may describe humans engaged in industry, but it turns out they describe humpback whales, too! The cooperative bubble-netting humpbacks of Southeast Alaska, so named for their use of nets formed by cylindrical columns of rising air emitted from their blowholes, exhibit all these attributes. In fact, they are one of the few animals aside from humans that do.

Dr. Fred Sharpe has been following bubble-netting humpbacks for more than two decades. By identifying individuals through their unique fluke patterns, he has come to know many of them quite well. There’s Captain Hook, leader-apparent in the bubble-netting pod that frequents Chatham Strait. And Melancholy, well-known for his haunting, melancholic ‘feeding call’ used to drive the prey – always herring for these animals – into the waiting net. In fact, Dr. Sharpe has identified about 60 regular bubble-netting participants among the 4000 or so whales that frequent Southeast Alaska during the summer foraging season

After two decades in the field, Dr. Sharpe has found that bubble-netting pods are formed by a relatively small subset of the Southeast humpback population

So why such social and behavioral complexity, which is unknown for other baleen whales? Herring are surprisingly quick and evasive prey. Presumably, by working together in this elaborate way bubble-netting humpbacks are able to capture far more fish than they could on their own. And just as human workers can operate more efficiently when we have established roles and enduring partnerships, it is likely humpback whales can as well!

We now know that humpbacks use 'feeding calls' to drive herring into the bubble-nets. What's even more remarkable than this form of tool use is that only a handful of animals in Southeast Alaska appear to specialize in this vocal behavior! Melancholy and Trumpeter are two such specialists, each named for the unique characteristics of their calls.

PREY RESEARCH

PREY RESEARCH

PREY RESEARCH

PREY RESEARCH

SUMMER FOR HUMPBACK WHALES IN ALASKA IS ALL ABOUT FORAGING. In the winter, North Pacific humpbacks travel to the sub-tropical waters of Hawaii, Mexico and Japan to mate and give birth, but in the spring they return north to feed. Therefore, if we want to understand their behavior in Alaska, we must consider their prey as well.

There's no way around it, surveying whale prey can be tedious work. For several field seasons, volunteers piloted rigid-hull inflatable boats (RIBs) along thousands of miles of predetermined transects at a slow 5 knots for 12 hours each day. The boats were outfitted with a sonar - a high tech fish finder that uses echolocation to shed light on what is happening below the waves - and a plankton net to collect krill samples. There weren’t always whales around. In fact, sometimes there weren’t even prey. But in science, the absence of something is often important data (so goes the aphorism: 'absence of evidence is not evidence of absence'), so the volunteers pressed on regardless.

NORTH TO THE FEEDING GROUNDS: Pretty much everything a humpback does in Alaska is related to feeding

KRILL CRUSADER Volunteers surveyed over 5,000 miles of transects, rain or shine using sonar and plankton nets mounted on rigid-hull inflatable boats.

So what can be done with all these prey data? For one, they can tell us a lot about prey dynamics in this comparatively unstudied region: How much does prey availability vary within or across years? Are there consistent prey ‘hot-spots’? Do different prey species vary in their reproductive and/or life history strategies? They can also provide the foundation for understanding whale abundance, distribution and behavioral patterns, and perhaps most importantly, how these patterns might change as our oceans succumb to rising temperatures, acidification and the overexploitation of marine resources.

Click HEREfor Dr. Szabo's publication on krill reproduction in Southeast Alaska, and HERE for his publication on humpback predation - or lack therefor - on juvenile krill. And stay tuned, as there are more to follow.

CITIZEN-SCIENCE

citizen-science

CITIZEN-SCIENCE

citizen-science

THE OCEANS ARE CHANGING. They're warming, becoming increasingly acidic, and sea levels are rising. Yet, it remains unclear how these perturbations will affect marine biological communities. Moreover, we lack the baseline data necessary to monitor how marine communities respond to environmental change. For marine mammals like humpback whales, these baseline data need to be collected over large areas and multiple years to be useful. Until recently, this was prohibitively costly and time consuming; however, scientists are increasingly turning to citizen-science programs as efficient, low-cost methods to collect large amounts of data.

Citizen-science programs encourage volunteers to participate in research by providing simple means for them to record important field data. Oregon State University graduate student and AWF biologist Courtney Hann is developing an application for a mobile platform that will allow boaters to record marine mammal sightings, while simultaneously raising their awareness of important conservation issues. Developing such an application is a collaborative process that will rely on the efforts of many volunteers. Hann hopes to engage boaters, including commercial fishermen, pleasure boaters, and charter vessel operators, through a targeted outreach program at AWF's Center for Coastal Conservation on Baranof Island .

Boaters who visit AWFs outreach center in Warm Springs Bay on Baranof Island can download a mobile application that allows them to log marine mammal sightings while cruising the waters of Southeast Alaska

AWF biologist Courtney Hann is hoping that citizen-science will be an effective way to develop regional-scale datasets for monitoring humpback whale populations

With the 2014 field season fast approaching and new research projects kicking off...

COW-CALF STUDIES

COW-CALF STUDIES

COW-CALF STUDIES

COW-CALF STUDIES

MOTHERS HAVE IT ROUGH. Their young need to be fed, require near-constant vigilance and have to be taught all the things they’ll need to know when it’s time to explore the world on their own. This is a particularly challenging task for humpbacks in Southeast Alaska, where an unattended calf is easy prey for hungry killer whales. So how can a lactating mother balance her own needs with those of her calf?

Dr. Szabo spent several field seasons observing humpback whale mother-offspring pairs in Southeast Alaska. These pairs tend to remain close to one another so mom can both nurse her calf and drive away hungry killer whales that might be looking for a meal. But young calves can’t dive as often or as long as their foraging mothers, so sometimes the two must separate. Dr. Szabo revealed that early on females sacrifice their own foraging needs by returning to the surface often to attend to their calves. But as the season progresses and the demands of lactation grow, calves are increasingly left to fend for themselves. Not wanting to be left behind and undoubtedly wanting to continue to nurse, the hungry calf soon begins to follow and is forced to begin supplementing its milk diet with food, such as krill, that it must catch itself.

UNOBTRUSIVE OBSERVER. By drifting quietly nearby four hours at a time, Dr. Szabo was afforded an intimate view into the lives of humpback mothers and their calves

A MOTHER'S LOVE. Humpback whale cow-calf pairs are solitary, and it is mom’s responsibility to locate food, nurse her calf, watch for predators, and, if lucky, find some time for rest.

Dr. Szabo cast these observations of changing priorities in light of a broad evolutionary theory called parent-offspring conflict. This theory suggests that at some point mothers should stop allocating energy to their present offspring and start conserving energy for their next one. Although the timing differs among different species, it always occurs at an age where juveniles can fend for themselves and mortality risk is low. However, this comes sooner than the offspring, who is more concerned with its own survival than its future siblings, might like. In some animals, the ensuing “conflict” is obvious; many hooved mammals can be seen forcibly driving their young away from their teats or actively avoiding their them. But until now, no instance of conflict has been observed among baleen whales.